(a) Field of the Invention
This invention relates to pipeline cleaning and plugging apparatus of the type which can be inserted into the pipeline through a side opening therein to clean and/or plug the same while the pipeline is pressurized.
(b) Description of the Prior Art
Many prior art devices have been developed for plugging a pipeline through a side opening while the pipeline is transmitting fluid or otherwise contains pressurized fluid. However, none of the prior art apparatus are fully successful for various reasons. Under certain conditions, the internal surface of a pipeline to be plugged may not be a uniform circle, having been deformed or having been obstructed by deposits, such as corrosion, or the like thereon. When this occurs, it is difficult to effect plugging thereof with prior art tools. Moreover, such prior art tools are deficient in that they lack means for adjusting the plugging head of the tool so as to accommodate variations in pipe diameters so as to co-axially or centrally position the seal means initially and to give added support to the plug assembly during the inserting operation. None of the prior art tools are easily adaptable to change them into a pipe cleaning tool so as to clean the internal surface of the pipe where the plug is to be made.